8722521 has 12 divisors (see below), whose sum is σ = 12647700. Its totient is φ = 5792640.

The previous prime is 8722517. The next prime is 8722541. The reversal of 8722521 is 1252278.

It can be written as a sum of positive squares in 2 ways, for example, as 2143296 + 6579225 = 1464^2 + 2565^2 .

It is not a de Polignac number, because 8722521 - 2² = 8722517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8722541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 805 + ... + 4253.

It is an arithmetic number, because the mean of its divisors is an integer number (1053975).

Almost surely, 2^8722521 is an apocalyptic number.

It is an amenable number.

8722521 is a deficient number, since it is larger than the sum of its proper divisors (3925179).

8722521 is a wasteful number, since it uses less digits than its factorization.

8722521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3736 (or 3733 counting only the distinct ones).

The product of its digits is 2240, while the sum is 27.

The square root of 8722521 is about 2953.3914403614. The cubic root of 8722521 is about 205.8483267866.

Adding to 8722521 its reverse (1252278), we get a palindrome (9974799).

The spelling of 8722521 in words is "eight million, seven hundred twenty-two thousand, five hundred twenty-one".